Support crash dumps > 4GB in size on 32 bit platforms. _kvm_kvatop()

returned an lseek offset in a "u_long *" value, which can't express >4GB
offsets on 32 bit machines (eg: PAE).  Change to "off_t *" for all.

Support ELF crashdumps on i386 and amd64.

Support PAE crashdumps on i386.  This is done by auto-detecting the
presence of the IdlePDPT which means that PAE is active.

I used Marcel's _kvm_pa2off strategy and ELF header reader for ELF support
on amd64.  Paul Saab ported the amd64 changes to i386 and we implemented
the PAE support from there.

Note that gdb6 in the src tree uses whatever libkvm supports.  If you want
to debug an old crash dump, you might want to keep an old libkvm.so handy
and use LD_PRELOAD or the like.  This does not detect the old raw dump
format.

Approved by: re

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/libkvm/kvm.c b/lib/libkvm/kvm.c
index 44a9e8c..9e97a78 100644
--- a/lib/libkvm/kvm.c
+++ b/lib/libkvm/kvm.c
@@ -369,7 +369,7 @@ kvm_read(kd, kva, buf, len)
 	} else {
 		cp = buf;
 		while (len > 0) {
-			u_long pa;
+			off_t pa;
 
 			cc = _kvm_kvatop(kd, kva, &pa);
 			if (cc == 0)
@@ -377,7 +377,7 @@ kvm_read(kd, kva, buf, len)
 			if (cc > len)
 				cc = len;
 			errno = 0;
-			if (lseek(kd->pmfd, (off_t)pa, 0) == -1 && errno != 0) {
+			if (lseek(kd->pmfd, pa, 0) == -1 && errno != 0) {
 				_kvm_syserr(kd, 0, _PATH_MEM);
 				break;
 			}